1. Field of the Invention
The present invention relates to a focus control apparatus comprising an optical engine for a display, and more particularly to a focus control apparatus for a display, in which the focus of a lens of an optical engine is easily adjusted by regulating the position of the lens.
2. Description of the Related Art
FIG. 1a is a schematic view of a conventional display for displaying image information.
With reference to FIG. 1a, the conventional display comprises an optical engine assembly 100, a mirror 200, and a screen 300. The optical engine assembly 100 serves to generate an image. The mirror 200 serves to reflect the image generated by the optical engine assembly 100. The image reflected by the mirror 200 is projected on the screen 300, thereby displaying the image.
The aforementioned conventional display analyzes an image signal transmitted from the external. Then, according to the analyzed image signal, the display generates an image through the optical engine assembly 100.
The image generated by the optical engine assembly 100 is reflected by the mirror 200, which is positioned on the rear of the display. Then, the image reflected by the mirror 200 is projected on the screen 300, which is positioned on the front of the display, thereby being displayed to users. In order to provide a high-quality picture to the users, the image must be exactly projected on the screen 300. The exact projection of the image on the screen 300 is obtained by focusing by the optical engine assembly 100.
FIG. 1b is a schematic view of the optical engine assembly 100 of the conventional display.
Hereinafter, with reference to FIG. 1b, the focus control system of the optical engine assembly 100 is described in detail.
As shown in FIG. 1b, the conventional optical engine assembly 100 comprises an optical engine 110 for generating an image, a lens 120, a connection tube 130, and a ring 140. Herein, the lens 120 serves to project the image generated by the optical engine 110. The connection tube 130 connects the optical engine 110 to the lens 120. The ring 140 serves to adjust the focus of the lens 120.
In order to adjust the focus of the lens 120, the ring 140 is rotated. The lens 120 is protruded from the connection tube 130 or intruded into the connection tube 130 by the rotation of the ring 140. Thereby, the focus of the lens 120 is adjusted.
In order to utilize this focus control system, the rear of the display is opened. Then, a worker puts his or her hand into the display and adjusts the focus of the lens 120 by hand. Therefore, the focusing using the aforementioned focus control system is very difficult and troublesome for the worker. Further, another problem is that it is difficult to check the projected condition of the image on the screen 300.
Moreover, the conventional focus control system additionally requires internal equipment for manipulating the lens 120.
This complicated structure of the display using the aforementioned focus control system causes frequent errors or defects.
Further, the complicated structure of the conventional display increases the production cost.